ExpandedRedstone by Reika
Expanded Redstone adds a few machines and tools that make redstone more useful and powerful. They are designed to 'feel' like vanilla, but work just as well in a heavily modded environment.
Rockhounding: Ore Tiers by GlobbyPotato
Turns the vanilla ores into tiers of them for a less cheaper and more challenging access to resources.
PlaceableEndCrystals by Virtuoel
A mod that allows End Crystals to be placed anywhere. Placement blacklisting and whitelisting is available in the config.
Instead of dropping your inventory on death, a grave will be dug in which a buried chest with your inventory and experience lies. The grave will be inscribed with your name and time of death. This helps to keep your things from getting lost or despawning.